Question

1. a student wants to test fertilizer type and fertilizer amount on plant growth. why would testing both variables at the same time be problematic? a) it would be impossible to know which factor caused the change b) plants cannot grow with more than one variable c) it makes the experiment more accurate d) it eliminates the need for a control group 2. two studies measured plant growth: study a used 5 plants, study b used 200 plants. both found similar results. which study is more reliable, and why? a) study a, because fewer plants reduce variation b) study b, because larger sample sizes reduce the effect of outliers c) study a, because smaller experiments are easier to control

Explanation:

1. Testing multiple variables simultaneously makes it impossible to determine which factor caused the change in plant growth. This violates the principle of a controlled - experiment where only one variable should be changed at a time.
2. Larger sample sizes generally reduce the effect of outliers and variation, making the results more reliable. Study B with 200 plants has a larger sample size compared to Study A with 5 plants.

Answer:

1. a) It would be impossible to know which factor caused the change.
2. b) Study B, because larger sample sizes reduce the effect of outliers.